The present technology provides a rubber composition having: from 30 to 50 parts by mass of carbon black having a nitrogen adsorption specific surface area of from 100 to 130 m.sup.2/g, from 25 to 40 parts by mass of carbon black having a nitrogen adsorption specific surface area of from 37 to 60 m.sup.2/g, from 1.5 to 2.2 parts by mass of sulfur as a pure sulfur content, and from 110 to 200 mass % of a sulfenamide-based vulcanization accelerator relative to the pure sulfur content compounded in 100 parts by mass of diene rubber containing from 30 to 60 parts by mass of isoprene rubber and from 40 to 70 parts by mass of butadiene rubber.

The present technology provides a rubber composition having: from 30 to 50 parts by mass of carbon black having a nitrogen adsorption specific surface area of from 100 to 130 m.sup.2/g, from 25 to 40 parts by mass of carbon black having a nitrogen adsorption specific surface area of from 37 to 60 m.sup.2/g, from 1.5 to 2.2 parts by mass of sulfur as a pure sulfur content, and from 110 to 200 mass % of a sulfenamide-based vulcanization accelerator relative to the pure sulfur content compounded in 100 parts by mass of diene rubber containing from 30 to 60 parts by mass of isoprene rubber and from 40 to 70 parts by mass of butadiene rubber.

A high-modulus rubber composition is based on at least a diene elastomer, a reinforcing filler, from 1 to 45 phr of reinforcing resin, from 1 to 10 phr of sulfur, and from 2 to 15 phr of vulcanization accelerator, in which the ratio of the content of sulfur to the content of vulcanization accelerator is less than 0.55.

A high-modulus rubber composition is based on at least a diene elastomer, a reinforcing filler, from 1 to 45 phr of reinforcing resin, from 1 to 10 phr of sulfur, and from 2 to 15 phr of vulcanization accelerator, in which the ratio of the content of sulfur to the content of vulcanization accelerator is less than 0.55.

Provided is a rubber composition having a high vulcanization rate and excellent in storage stability. The rubber composition contains a rubber component that contains at least one type of a dienic rubber, a filler, a vulcanizing agent, a compound represented by a formula (1), a compound represented by a formula (2), and a vulcanization accelerator except the compound represented by the formula (1), wherein the total amount of the vulcanization accelerator and the compound represented by the formula (1) is 1.3 to 2.0 parts by mass relative to 100 parts by mass of the rubber component.

##STR00001##

Provided is a rubber composition having a high vulcanization rate and excellent in storage stability. The rubber composition contains a rubber component that contains at least one type of a dienic rubber, a filler, a vulcanizing agent, a compound represented by a formula (1), a compound represented by a formula (2), and a vulcanization accelerator except the compound represented by the formula (1), wherein the total amount of the vulcanization accelerator and the compound represented by the formula (1) is 1.3 to 2.0 parts by mass relative to 100 parts by mass of the rubber component.

##STR00001##

Provided is a rubber composition having a high vulcanization rate and excellent in storage stability. The rubber composition contains a rubber component that contains at least one type of a dienic rubber, a filler, a vulcanizing agent, a compound represented by a formula (1), a compound represented by a formula (2), and a vulcanization accelerator except the compound represented by the formula (1), wherein the total amount of the vulcanization accelerator and the compound represented by the formula (1) is 1.3 to 2.0 parts by mass relative to 100 parts by mass of the rubber component.

##STR00001##

An NBR composition for rubber laminated metal, having 1 to 3 parts by weight of sulfur and 1 to 15 parts by weight of a disulfide compound such as 4,4-dithiodimorpholine or dithiocaprolactam represented by the general formula RN-S-S-NR (wherein RN is a cyclic linking group formed together with the N atom bonded to the S atom), based on 100 parts by weight of NBR. The rubber composition that can improve the protrusion properties of a rubber layer when used for, for example, a gasket or a brake shim material that is a laminated composite metal laminated with another metal plate.

An NBR composition for rubber laminated metal, having 1 to 3 parts by weight of sulfur and 1 to 15 parts by weight of a disulfide compound such as 4,4-dithiodimorpholine or dithiocaprolactam represented by the general formula RN-S-S-NR (wherein RN is a cyclic linking group formed together with the N atom bonded to the S atom), based on 100 parts by weight of NBR. The rubber composition that can improve the protrusion properties of a rubber layer when used for, for example, a gasket or a brake shim material that is a laminated composite metal laminated with another metal plate.

An NBR composition for rubber laminated metal, having 1 to 3 parts by weight of sulfur and 1 to 15 parts by weight of a disulfide compound such as 4,4-dithiodimorpholine or dithiocaprolactam represented by the general formula RN-S-S-NR (wherein RN is a cyclic linking group formed together with the N atom bonded to the S atom), based on 100 parts by weight of NBR. The rubber composition that can improve the protrusion properties of a rubber layer when used for, for example, a gasket or a brake shim material that is a laminated composite metal laminated with another metal plate.